Question

. Compare and contrast Asymmetric Key Algorithm's: RSA, Diffie-Hellman, and Elliptic Curve vs Symmetric Key Algorithms: Triple DES, Twofish, RC(6), and AES then please discuss what is your personal preferred method of encryption and why?

Answer 1

Ans:

Difference Between Symmetric and Asymmetric Encryption:

While communicating on an unsecured medium like the internet, you have to be careful about the confidentiality of the information you are sharing with other. The are two techniques use to preserve the confidentiality of your message, Symmetric and Asymmetric Encryption. The fundamental difference that distinguishes symmetric and asymmetric encryption is that symmetric encryption allows encryption and decryption of the message with the same key. On the other hand, asymmetric encryption uses the public key for the encryption, and a private key is used for decryption.

BASIS FOR COMPARISON	SYMMETRIC ENCRYPTION	ASYMMETRIC ENCRYPTION
Basic	Symmetric encryption uses a single key for both encryption and Decryption.	Asymmetric encryption uses a different key for encryption and decryption.
Performance	Symmetric encryption is fast in execution.	Asymmetric Encryption is slow in execution due to the high computational burden.
Algorithms	DES, 3DES, AES, and RC4.	Diffie-Hellman, RSA.
Purpose	The symmetric encryption is used for bulk data transmission.	The asymmetric encryption is often used for securely exchanging secret keys.

Symmetric Encryption

Symmetric encryption is a technique which allows the use of only one key for performing both the encryption and the decryption of the message shared over the internet. It is also known as the conventional method used for encryption. In symmetric encryption, the plaintext is encrypted and is converted to the ciphertext using a key and an encryption algorithm. While the cipher text is converted back to plain text using the same key that was used for encryption, and the decryption algorithm.

Symmetric encryption algorithm executes faster and is less complex hence; they are used for bulk data transmission. In symmetric encryption, the host that are participating in the communication already have the secret key that is received through the external means. The sender of the message or information will use the key for encrypting the message, and the receiver will use the key for decrypting the message. The commonly used symmetric encryption algorithms are DES, 3 DES, AES, RC4.

Asymmetric Encryption:

Asymmetric encryption is an encryption technique that uses a pair of key (private key and public key) for encryption and decryption. Asymmetric encryption uses the public key for the encryption of the message and the private key for the decryption of the message. The public key is freely available to anyone who is interested in sending the message. The private key is kept secret with the receiver of the message. Any message that is encrypted by the public key and the algorithm, is decrypted using the same the algorithm and the matching private key of corresponding public key.

The asymmetric encryption algorithm execution is slow. As asymmetric encryption algorithm are complex in nature and have the high computational burden. Hence, the asymmetric encryption is used for securely exchanging the keys instead of the bulk data transmission. Asymmetric encryption is generally used for establishing a secure channel over the non-secure medium like the internet. The most common asymmetric encryption algorithm are Diffie-Hellman and RSA algorithm.

Key Differences Between Symmetric and Asymmetric Encryption

1. Symmetric encryption always uses a single key for encryption and decryption of the message. However, in asymmetric encryption, the sender uses the public key for the encryption and private key for decryption.
2. The execution of asymmetric encryption algorithms is slower as compared to the symmetric encryption algorithm. This is because the asymmetric encryption algorithms are more complex and has the high computational burden.
3. The symmetric encryption algorithms that are most commonly used are DES, 3DES, AES and RC4. On the other hand, Diffie-Hellman and RSA area the most common algorithm used for asymmetric encryption.
4. The asymmetric encryption is generally used for exchanging secret keys whereas, the symmetric encryption is used for exchanging a bulk of data

One of the best encryption method:

AES:

The Advanced Encryption Standard, AES, is a symmetric encryption algorithm and one of the most secure. The United States Government use it to protect classified information, and many software and hardware products use it as well. This method uses a block cipher, which encrypts data one fixed-size block at a time, unlike other types of encryption, such as stream ciphers, which encrypt data bit by bit.

AES is comprised of AES-128, AES-192 and AES-256. The key bit you choose encrypts and decrypts blocks in 128 bits, 192 bits and so on. There are different rounds for each bit key. A round is the process of turning plaintext into cipher text. For 128-bit, there are 10 rounds; 192-bit has 12 rounds; and 256-bit has 14 rounds.